Neil Armstrong, the first man to walk on the moon, stands next to a lunar landing simulator at the National Aeronautics and Space Administration Langley Research Center in Hampton, Va., January 28, 1970. NASA scientists realized a manned capsule would handle drastically differently in the moon’s gravitational atmosphere, which is a sixth of that felt on Earth. Tackling the problem of how to reproduce a low-gravitational environment became NASA’s first step on the road to the moon. (NASA courtesy photo/Released)